JPH054942A - Acrylate compound and dental adhesive - Google Patents

Abstract

PURPOSE:To obtain a new mono(meth)acrylate-based compound having excellent balance of adhesiveness, side and edge sealing properties, hydrophilic nature, etc., as a dental adhesive. CONSTITUTION:A mesoerythritol monoacrylate and mesoerythritol monomethacrylate shown by formula I (R is H or CH3). The compound is produced by adding mesoerythritol to a mixed solution of dimethylformamide and pyridine, then adding 2,3,5,6-tetramethylhydroquinone and 4- dimethylaminopyridine and reacting at room temperature. A dental adhesive comprising (A) the compound shown by formula I and/or formula II and (B) at least one olefinic double bond-containing monomer copolymerizable with the compound A has not only excellent adhesiveness but side and edge sealing of suppressing formation of gap at side and edge of dentine and restorative dental material and excellent balance of hydrophilic nature.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a dental adhesive which is excellent in adhesiveness between a tooth substance and a dental restorative material and edge sealing property.

[0002]

BACKGROUND OF THE INVENTION In the field of dental materials, various adhesives have been developed in recent years, which have excellent adhesiveness to dentin, especially dentin. A polymerizable monomer having an acidic group in its molecule is used as an adhesive component of an adhesive used in the technical field of dental materials. For example, (meta)
Phosphoric acid diester group is added to acrylic acid-based compounds
2-113089), phosphoric acid monoester group (Japanese Patent Laid-Open No.
58-21607), a carboxy group, an acid anhydride group (see JP-A-54-11149), and an acid halide group (see JP-A-57-151607). It is a monomer.

In addition to the (meth) acrylic acid type compound having the above-mentioned group, hydroxyethyl (meth) acrylate (HE) is used as an adhesive component of a general adhesive.
An adhesive using a (meth) acrylic acid ester of a polyhydroxy compound such as MA) or glyceryl mono (meth) acrylate (GM) is also used.

However, the dental restorative material is used under harsh conditions that are not comparable to the so-called general adhesive application. Therefore, in such applications, in addition to the properties of conventional adhesives, it is necessary to have a good balance of performances such as adhesiveness, marginal sealing property and hydrophilicity.

The inventor of the present invention has found that in such a dental adhesive, the number of hydroxy groups contained in the (meth) acrylate-based polymerizable monomer is such that the adhesiveness, the margin blocking property and the hydrophilicity are high. The present invention has been reached by finding that it has a great influence on the balance of

[0006]

OBJECT OF THE INVENTION It is an object of the present invention to provide a novel (meth) acrylate compound.

Further, the present invention is a dental adhesive using the above-mentioned (meth) acrylate compound, and in addition to having excellent adhesiveness, a gap is formed at the margin between the tooth substance and the restorative material. It is an object of the present invention to provide a dental adhesive which is excellent in the balance between the marginal sealing property and the hydrophilicity of the adhesive.

[0008]

SUMMARY OF THE INVENTION The mesoerythritol mono (meth) acrylate of the present invention is represented by the following formula [1].

[0009]

[Chemical 5]

[1] In the formula [1], R represents a hydrogen atom or a methyl group. Further, the dental adhesive of the present invention comprises a mesoerythritol mono (meth) acrylate represented by the above formula [1] and / or a pentaerythritol mono (meth) acrylate represented by the following formula [2], It is characterized by containing a (meth) acrylate compound and a polymerizable monomer having at least one olefinic double bond which is copolymerizable.

[0011]

[Chemical 6]

[2] In the formula [2], R represents a hydrogen atom or a methyl group. The present invention provides a novel mono (meth) acrylate compound.

The mono (meth) acrylate compound represented by the formula [1] or the formula [2] has three hydroxy groups in the molecule. As described above, the dental adhesive containing the mono (meth) acrylate compound having three hydroxy groups has a very good balance of performances such as adhesiveness, edge sealing property and hydrophilicity.

[0014]

DETAILED DESCRIPTION OF THE INVENTION First, the novel acrylate compound of the present invention will be explained. The acrylate compound provided by the present invention is mesoerythritol mono (meth) acrylate represented by the following formula [1].

[0015]

[Chemical 7]

[1] However, in the above formula [1], R represents a hydrogen atom or a methyl group. Therefore, the acrylate compounds provided by the present invention include mesoerythritol monoacrylate and mesoerythritol monomethacrylate.

Such mesoerythritol mono (meth) acrylate can be prepared, for example, as follows. First, mesoerythritol was added to a mixed solution of dimethylformamide and pyridine, and the mixed solution was further mixed with 2,3,5,6-tetramethylhydroquinone and
Add 4-dimethylaminopyridine. While cooling this mixed solution, (meth) acryloyl chloride is gradually added with stirring. The (meth) acryloyl chloride added here is added in an amount of 1 mol or more, preferably 1 to 2 mol, relative to 1 mol of mesoerythritol. After the addition of (meth) acryloyl chloride in this manner, the reaction is usually continued for about 5 hours while the temperature of the reaction solution is gradually returned to room temperature. The (meth) acryloyl mesoerythritol [that is, mesoerythritol mono (meth) acrylate] can be obtained by separating the obtained reaction liquid using a separation means such as column chromatography. The (meth) acrylate compound thus obtained is mainly 1- O-
(Meth) acryloyl mesoerythritol. Such mesoerythritol mono (meth) acrylate is preferably stored in a small amount of hydroquinone.

The dental adhesive of the present invention comprises the above mesoerythritol mono (meth) acrylate and / or pentaerythritol mono (meth) represented by the following formula [2].
It comprises an acrylate and a polymerizable monomer having at least one olefinic double bond which is copolymerizable with these mono (meth) acrylate compounds.

[0019]

[Chemical 8]

[2] In the above formula [2], R represents a hydrogen atom or a methyl group. The pentaerythritol mono (meth) acrylate used here can be prepared, for example, by using pentaerythritol instead of mesoerythritol in the method for preparing mesoerythritol mono (meth) acrylate.

In the present invention, when the term "mono (meth) acrylate compound" is used without any particular limitation, it means that it includes both compounds represented by the formulas [1] and [2]. .

Since both of these mono (meth) acrylate compounds have three hydroxyl groups in the molecule, by using this compound, the surface of the adhesive to be bonded (tooth surface) is expected.
It is possible to obtain a dental adhesive that has improved wettability (affinity) with respect to, and is excellent in adhesiveness to tooth substance and edge sealing property. The present applicant has already proposed a dental adhesive using glyceryl mono (meth) acrylate having two hydroxyl groups in the molecule (Japanese Patent Application No. 2-81768 and Japanese Patent Application No. 2-81769). See the book). Comparing the adhesive containing the glyceryl mono (meth) acrylate with the adhesive of the present invention containing the mono (meth) acrylate compound, the adhesive of the present invention shows adhesiveness, affinity for tooth structure and marginal blockage. It shows even better values for properties such as properties. When an acrylate-based compound having four or more hydroxyl groups in the molecule is used, properties such as wettability are improved, but on the contrary, properties such as adhesive water resistance tend to be deteriorated. When viewed comprehensively as a dental adhesive, the balance of adhesiveness, affinity and edge sealing property is not good.

Among such mono (meth) acrylate compounds, mesoerythritol mono (meth) acrylate represented by the formula [1] includes mesoerythritol monoacrylate and mesoerythritol monomethacrylate. The pentaerythritol mono (meth) acrylate represented by 2] includes pentaerythritol monoacrylate and pentaerythritol monomethacrylate. In the dental adhesive of the present invention, these can be used alone or in combination.

The polymerizable monomer used in the present invention includes (meth) acrylic acid ester, (meth) acrylamide, maleic acid ester, fumaric acid ester and vinyl esters such as vinyl acetate, styrene and its derivatives, and , Vinyl compounds such as acrylonitrile and acrolein. Among these, (meth) acrylic acid ester is preferable.

Examples of the (meth) acrylic acid ester preferably used in the present invention include methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, ethylene glycol di (meth) acrylate and triethylene glycol di (meth). ) Acrylate, neopentyl glycol di (meth) acrylate, 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane (Bis- GMA), trimethylolethane tri (meth) acrylate, penta Mention may be made of erythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate and N, N-dimethylaminoethyl methacrylate.

Further, in the present invention, as the polymerizable monomer,

[0027]

[Chemical 9]

At least one kind of polar group represented by
An acidic polymerizable monomer having at least one olefinic double bond is preferably used. Examples of such acidic polymerizable monomers include the compounds described below.

[0029]

[Chemical 10]

[0030]

[Chemical 11]

[0031]

[Chemical 12]

[0032]

[Chemical 13]

[0033]

[Chemical 14]

[0034]

[Chemical 15]

[0035]

[Chemical 16]

[0036]

[Chemical 17]

[0037]

[Chemical 18]

[0038]

[Chemical 19]

[0039]

[Chemical 20]

[0040]

[Chemical 21]

[0041]

[Chemical formula 22]

[0042]

[Chemical formula 23]

[0043]

[Chemical formula 24]

[0044]

[Chemical 25]

[0045]

[Chemical formula 26]

[0046]

[Chemical 27]

The dental adhesive of the present invention, as described above,
It is formed of a (meth) acrylate compound and a polymerizable monomer (preferably an acidic polymerizable monomer) capable of copolymerizing with the (meth) acrylate compound. It can be used in such a manner.

(A) a (meth) acrylate compound,
Use as a mixture with this (meth) acrylate compound and a polymerizable monomer having at least one olefinic double bond capable of copolymerization (preferably a part of the polymerizable monomer contains the acidic polymerizable monomer) To do. In this case, if necessary, a third component such as a solvent, a filler and a polymerization initiator may be added to this mixture.

In the adhesive composed of such a mixture, the (meth) acrylate compound is added to the total weight.
0.01 to 50% by weight (more preferably 0.1 to 30)
It is preferably contained in an amount of% by weight. The acidic polymerizable monomer is preferably contained in an amount of 0.01 to 50% by weight (more preferably 0.1 to 30% by weight).

The dental adhesive configured as described in (a) above is a one-component type and is easy to handle as compared with the dental adhesive configured as described in (b) below. Yes,
Further, it can be used without any practical problem in storage stability.

The dental adhesive of the present invention used in the form of such a mixture is used by applying it to dentin, particularly dentin. (B) A composition [A] containing a (meth) acrylate compound and a polymerizable monomer having at least one olefinic double bond copolymerizable with the (meth) acrylate compound (preferably acidic polymerization). The composition [B] containing the polymerizable monomer) is packaged separately and stored so that the two components do not come into contact with each other. That is, the package of the composition [A] and the package of the composition [B] are separately stored, and the composition [A] and the composition [B] are used in a mixed state before use. . In addition, the package of the composition [A] and the package of the composition [B] are
The composition [A] and the composition [B] may be stored so as not to come into contact with each other during storage, and the package may be removed and mixed so that the two compositions may come into contact immediately before use.

That is, in the former case, the dental adhesive is applied such that the composition [A] is first applied to the dentin, particularly the dentin (adhering surface), and then the composition [B] is laminated. Used. In the latter case, each package is removed immediately before use and the contents are mixed and used.

Composition [A] used in such an embodiment
May contain, in addition to the (meth) acrylate compound, a solvent having a boiling point of 200 ° C. or less at normal pressure, for example, a volatile organic solvent, water or a mixture thereof. In addition, a polymerization initiator, a filler, and the like may be added to the composition [A], if necessary. In the composition [A],
The (meth) acrylate compound is 0.
It is preferably contained in an amount of 1 to 80% by weight (more preferably 1 to 50% by weight).

In the composition [B], a polymerization initiator is usually compounded in addition to the above polymerizable monomer. Furthermore, the composition [B] may contain a solvent, a filler, and the like, if necessary. In addition, this composition [B]
May be of two-part packaging type, if necessary.

The acidic polymerizable monomer in the above composition [B] is 0.01 to 50% by weight (more preferably 0.1% by weight).
It is preferably contained in an amount of 1 to 30% by weight). In the above embodiment, the use ratio (weight) of the composition [A] and the composition [B] is set within the range of 1: 100 to 10: 1 (more preferably 1:10 to 2: 1). preferable.

The dental adhesive of the present invention may contain a solvent having a specific temperature or lower. Examples of such a solvent include water having a boiling point of 100 ° C. at room temperature and a volatile organic solvent having a boiling point of 200 ° C. or less at normal pressure. Examples of such volatile organic solvents include alcohols such as methanol, ethanol, allyl alcohol, isopropanol and 1-octanol; ketones such as acetone, methyl ethyl ketone and holone; ethyl ether, 1,4-dioxane and diethylene glycol. Ethers; esters such as ethyl acetate, butyl acetate and 2-ethylhexyl acetate; and hexane, undecane, toluene, xylene, methylene chloride, 1,2-dichloroethane and 1,1,
2,2-tetrachloroethane and the like can be mentioned. Water or the above volatile organic solvent may be used alone or in a mixture.

A polymerization initiator may be blended in the dental adhesive of the present invention. Examples of such a polymerization initiator include a benzoyl peroxide-aromatic tertiary amine-based mixture and cumene hydro. Peroxides such as peroxides; tributylborane, aromatic sulfinic acid (or a salt thereof) -aromatic secondary or tertiary amine-acyl peroxide mixture, and the like. further,
Examples include α-diketones (eg camphorquinone, diacetyl, benzyl) -reducing agents (eg tertiary amines, aldehydes, mercaptans) and photopolymerization initiators such as benzoin methyl ether.

Examples of fillers that can be incorporated into the dental adhesive of the present invention include inorganic fillers such as glass, quartz, hydroxyapatite, calcium carbonate, barium sulfate, aluminum oxide, titanium oxide and zirconium oxide, Mention may be made of polymer powders such as polymethylmethacrylate powders, polystyrene powders and polyvinyl chloride powders.

The dental adhesive of the present invention can be used in the same manner as a commonly used dental adhesive.
That is, for example, the dental adhesive of the present invention is applied to the planned bonding surface of the tooth structure, and then a dental restorative material such as a composite resin or metal is placed on the surface coated with the dental adhesive, The adhesive is cured to bond the tooth substance and the dental restorative material.

[0060]

The present invention provides mesoerythritol mono (meth) acrylate, which is a novel acrylate compound.

The dental adhesive according to the present invention has excellent adhesiveness to tooth structure, particularly dentin, and excellent sealing property of the margin between the tooth structure and the restorative material. Therefore, the dental adhesive of the present invention can be used for various dental applications in which such effects are required, but is particularly suitable for restoration of a tooth having a dental caries disease, particularly for restoration including a tooth neck. Used for.

The contents of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0063]

EXAMPLE 1 [1-O - methacryloyl Preparation of meso-erythritol] mesoerythritol (MESO -Erythritol) as a powder 12.2
11 g (0.100 mol) of dimethylformamide (dimehtylf
ormamide, hereinafter "DMF") 60 ml and pyridine (pyridine) 1
Suspend in a mixture with 5 ml (14.73 g, 0.186 mol) and add 4-
200 mg of dimethylaminopyridine (hereinafter, "DMAP") and 100 mg of 2,3,5,6-tetramethylhydroquinone (2,3,5,6-tetramethylhydroquinone) were added, and the whole mixture was placed on a water bath at about 40 ° C. Heat while shaking. A nearly homogeneous solution is obtained. When this solution was cooled to 0 to 5 ° C while stirring in ice water, a small amount of crystals were precipitated.

While keeping the liquid temperature of this solution at 5 ° C. or lower, the solution was added to methacryloyl chloride (met) under continuous stirring.
13.1 ml (14.0 g, 0.134 mol) of hacryloyl chloride) is dropped little by little. When about 3 ml of the reagent was added dropwise, the precipitated crystals were completely dissolved and became a slightly yellow uniform liquid. The dropping was completed over 2 hours and 30 minutes, the slightly yellow transparent reaction solution was gradually stirred and returned to room temperature, and stirring was continued for another 5 hours.

The reaction solution was evaporated under reduced pressure on a water bath at 40 ° C. or lower to obtain a slightly yellow syrupy residue. This is dissolved in 30 ml of a mixture of chloroform and ethanol and purified by column chromatography using 150 g of silica gel.

Mixture of chloroform and ethanol (CHC
l ₃ : EtOH = 95: 5), and collect the effluent that gives a single spot near Rf = 0.3 by thin layer chromatography (developing solvent; CHCl ₃ : EtOH = 95: 5). Then the solvent is removed to obtain about 3.5 to 5.5 g of a colorless oily substance.

The infrared absorption spectrum of the obtained reaction product was measured by the KBr tablet method. Furthermore, 4
Using a 00 megacycle nuclear magnetic resonance spectrometer,
¹ H-NMR spectrum was measured in a solvent of dimethyl sulfoxide-d ₆ using tetramethylsilane as an internal standard.

The main peaks of the infrared absorption spectrum and their assignments are as follows. ν KBr (cm ^-1 ): 3400 (-OH), 1707
(Ester, C = O), 1640 (C = O), 1190
The peaks of the (ester, C—O—C) ¹ H-NMR spectrum and their assignments are as follows.

Δ (ppm in DMSO-d₆): 1.88 (3
H, s, = C-CH ₃  ), 3.40 (2H, m, -C)H
₂ -OH), 3.55 (1H, m, -CH-OH), 3.
61 (1H, m, -CH-OH), 4.04 (1H, d
d, J = 7Hz, 11Hz, COO-CH-), 4.2
4 (1H, dd, J = 3Hz, 11Hz, COO-CH
-), 5.65 (1H, s, = CH), 6.06 (1
H, s, = CH) From the above analysis results, the product is only the 1-position hydroxyl group
Is esterified 1-O-Methacryloyl mesoerythritol
Was confirmed to be This 1-O-Methacryloyl
For mesoerythritol, add a small amount of hydroquinone.
Therefore, it can be stably stored for a long period of time.

The above reaction is expressed by the following formula.

[0071]

[Chemical 28]

[Adhesion test] A flat surface of extracted human dentin treated with an aqueous EDTA solution having a concentration of 0.5 mol / liter for 60 seconds was added with 35 parts by weight of 1- O -methacryloyl mesoerythritol and 65 parts by weight of water. The composition [A-1] was applied and blown with air.

Then, a commercial dental adhesive containing 10-methacryloyloxydecyldihydrodiene phosphate (Clearfill New Bond, manufactured by Kuraray Co., Ltd.) containing 10-methacryloyloxydecyldihydrogen phosphate was applied to the coated surface, and after air blowing, Commercially available composite resin clear fill FII (Kuraray Co., Ltd.)
Was manufactured and cured.

Ten samples prepared as described above were immersed in 37 ° C. water for 24 hours, and the tensile adhesive strength was measured. The results are shown in Table 1.

Eliminate the adjacent enamel of 10 extracted molars, 3 mm diameter on dentin flattened with 1000 polishing paper,
A cylindrical cavity having a depth of 1.5 mm was formed. Then, the inside of the cavity was treated with an aqueous EDTA solution having a concentration of 0.5 mol / liter for 60 seconds, washed with water and dried, and then the composition [A-1] was applied to the entire cavity and blown with air. Furthermore, after applying clear fill new bond and air blowing, clear fill FII
The cavity was filled and cured.

Immediately after immersing in room temperature water and leaving for 10 minutes, the filled part is mirror-polished to expose the cavity edge, and the gap between the cavity and the filler interface is observed with an optical microscope (NIKON, OPTIPHOTO, × 400).
Was observed using.

With respect to 8 out of 10 samples, no gap was observed over the entire circumference of the fossa rim, and a good joined state was shown. Width of shrinkage gap for all samples is 0-0.06
μm, and the average value was 0.01 ± 0.01 μm.

[0078]

[Example 2] In Example 1, except that the composition [A-1] was replaced by a composition [A-2] consisting of 40 parts by weight of 1- O -methacryloyl mesoerythritol and 60 parts by weight of water. Similarly, the adhesive strength and the width of the shrinkage gap were measured.

The results are shown in Table 1. Further, in all of the 10 samples, no gap was observed over the entire circumference of the fossa, and a good joined state was shown.

[0080]

Example 3 [Preparation of 1- O -methacryloylpentaerythritol] Pentaerythritol 1 as powder
3.615 g (0.100 mol) of DMF 60 ml and pyridine (p
yridine) 15 ml (14.73 g, 0.186 mol) and suspended in a mixed solution, DMAP 200 mg and 2,3,5,6-tetramethylhydroquinone (2,3,5,6-tetramethylhydroquinone) 100 m
g and warm the whole mixture with shaking on a water bath at about 40 ° C. A nearly homogeneous solution is obtained. When this solution was cooled to 0 to 5 ° C while stirring in ice water, a small amount of crystals were precipitated.

While keeping the liquid temperature of this solution at 5 ° C. or lower, the solution was added to methacryloyl chloride (met) under continuous stirring.
13.1 ml (14.0 g, 0.134 mol) of hacryloyl chloride) is dropped little by little. When about 3 ml of the reagent was added dropwise, the precipitated crystals were completely dissolved and became a slightly yellow uniform liquid. The dropping was completed over 2 hours and 30 minutes, the slightly yellow transparent reaction solution was gradually stirred and returned to room temperature, and stirring was continued for another 5 hours.

The reaction solution was evaporated under reduced pressure on a water bath at 40 ° C. or lower to obtain a slightly yellow syrupy residue. This is dissolved in 30 ml of a mixture of chloroform and ethanol and purified by column chromatography using 150 g of silica gel.

Mixture of chloroform and ethanol (CHC
l ₃ : EtOH = 95: 5) and collect the effluent that gives a single spot around Rf = 0.3 by thin layer chromatography (developing solvent; CHCl ₃ : EtOH = 90: 10). Then the solvent is removed to obtain about 3.6 to 5.2 g of colorless oily substance.

The infrared absorption spectrum of the obtained reaction product was measured by the KBr tablet method. Furthermore, 4
Using a 00 megacycle nuclear magnetic resonance spectrometer,
¹ H-NMR spectrum was measured in a solvent of dimethyl sulfoxide-d ₆ using tetramethylsilane as an internal standard.

The main peaks of the infrared absorption spectrum and their assignments are as follows. ν KBr (cm ⁻¹ ): 3400 (-OH), 1710
(Ester, C = O), 1635 (C = O), 1200
The peaks of the (ester, C—O—C) ¹ H-NMR spectrum and their assignments are as follows.

Δ (ppm in DMSO-d ₆ ): 1.89 (3
H, s, = C-C H 3), 3.39 (6H, d, -C H
_2- OH × 3, D ₂ O → s), 3.98 (2H, s, -C
_{OO-C H 2 -),} 5.63 (1H, s, = C- H),
6.2 (1H, s, = C- H) from above-described analysis results, the product only one 1-hydroxyl group is 1-O esterified - it was confirmed that the methacryloyl pentaerythritol . This 1- O -methacryloylpentaerythritol can be stably stored for a long time by adding a small amount of hydroquinone.

The above reaction is represented by the following formula.

[0088]

[Chemical 29]

[Adhesion Test] The surface was polished with ^# 1000 polishing paper, and then ED at a concentration of 0.5 mol / liter.
A composition [A-3] consisting of 20 parts by weight of 1- O -methacryloylpentaerythritol and 80 parts by weight of water was applied to the flat surface of the extracted human dentin treated with an aqueous TA solution for 60 seconds, and air blown.

Then, a commercial dental adhesive containing 10-methacryloyloxydecyldihydrodiene phosphate (Clearfill New Bond, manufactured by Kuraray Co., Ltd.) containing 10-methacryloyloxydecyldihydrodiene phosphate was applied to the coated surface, and after air blowing, Commercially available composite resin clear fill FII (Kuraray Co., Ltd.)
Was manufactured and cured.

Ten samples prepared as described above were immersed in water at 37 ° C. for 24 hours, and the tensile adhesive strength was measured. The results are shown in Table 1.

Adjacent enamel of 10 extracted molars was removed, and a cylindrical cavity having a diameter of 3 mm and a depth of 1.5 mm was formed on the dentin flattened with ^# 1000 polishing paper. Then
The inside of the cavity was treated with an aqueous EDTA solution having a concentration of 0.5 mol / liter for 60 seconds, washed with water and dried, and then the composition [A-3] was applied to the entire cavity and blown with air. Further, clear fill new bond was applied, and after air blowing, clear fill FII was filled in the cavity and cured.

Immediately after immersing in water at room temperature for 10 minutes, the filled part was mirror-polished to expose the cavity edge, and the gap between the cavity and the filler interface was observed using an optical microscope (NIKON, OPTIPHOTO × 400). .

A gap was observed over the entire circumference of the fossa of 10 samples, but a good bonding state was shown. The width of the shrinkage gap for all samples was 0.03-0.17 μm and the average value was 0.08 ± 0.05 μm.

[0095]

[Example 4] In Example 3, except that the composition [A-3] was replaced by a composition [A-4] consisting of 35 parts by weight of 1- O -methacryloylpentaerythritol and 65 parts by weight of water. Similarly, the adhesive strength and the width of the shrinkage gap were measured.

The results are shown in Table 1. 5 out of 10 samples
Regarding the individual pieces, no gap was observed over the entire circumference of the fossa, showing a good joined state. The width of the shrinkage gap for all samples is 0-0.04 μm and the average value is 0.01
It was ± 0.01 μm.

[0097]

[Example 5] In Example 3, except that the composition [A-3] was replaced by a composition [A-5] consisting of 40 parts by weight of 1- O -methacryloylpentaerythritol and 60 parts by weight of water. Similarly, the adhesive strength and the width of the shrinkage gap were measured.

The results are shown in Table 1. 5 out of 10 samples
Regarding the individual pieces, no gap was observed over the entire circumference of the fossa, showing a good joined state. The width of the shrinkage gap for all samples is 0-0.08 μm and the average value is 0.02
It was ± 0.03 μm.

[0099]

Example 6 In Example 3, the composition [A-6] was replaced by a composition [A-6] consisting of 45 parts by weight of 1- O -methacryloylpentaerythritol and 55 parts by weight of water. Similarly, the adhesive strength and the width of the shrinkage gap were measured.

The results are shown in Table 1. 5 out of 10 samples
Regarding the individual pieces, no gap was observed over the entire circumference of the fossa, showing a good joined state. The width of the shrinkage gap for all samples is 0-0.06 μm and the average value is 0.02
It was ± 0.02 μm.

[0101]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sadao Wakumoto             3-43-14-702 Hongo, Bunkyo-ku, Tokyo (72) Inventor Sada Miya Miya             1-27-11 Aobadai, Midori-ku, Yokohama-shi, Kanagawa

Claims (6)

[Claims] 1. Mesoerythritol mono (meth) acrylate represented by the following formula [1]: ... [1] (In the formula [1], R represents a hydrogen atom or a methyl group). 2. A mesoerythritol mono (meth) acrylate represented by the following formula [1] and / or a pentaerythritol mono (meth) acrylate represented by the following formula [2], together with the (meth) acrylate compound. A dental adhesive containing a polymerizable monomer having at least one polymerizable olefinic double bond; ... [1] ... [2] (In the formulas [1] and [2], R represents a hydrogen atom or a methyl group). 3. The dental adhesive comprises mesoerythritol mono (meth) acrylate and / or pentaerythritol mono (meth) acrylate, and the mono (meth) acrylate.
The dental adhesive according to claim 2, which is a one-pack mixture with an acrylate compound and a polymerizable monomer having at least one olefinic double bond which is copolymerizable. 4. The dental adhesive comprises an adhesive component containing mesoerythritol mono (meth) acrylate and / or pentaerythritol mono (meth) acrylate and at least one copolymerizable with the mono (meth) acrylate compound. The adhesive component containing a polymerizable monomer having olefinic double bonds is individually packaged, and both components are held in a non-contact state. Dental adhesive. 5. Mesoerythritol mono (meth) acrylate and / or pentaerythritol mono (meth) acrylate
The dental adhesive according to any one of claims 2 to 4, wherein the acrylate is dissolved in a solvent having a boiling point of 200 ° C or less at normal pressure. 6. The polymerizable monomer according to claim 2, which has at least one olefinic double bond and at least one kind of acidic group selected from the group shown below. The dental adhesive described above; (However, in the above formula, Z represents a halogen atom,
The bond has a hydroxyl group, a halogen atom or -PO (O
H) -O- group is not bonded).